Improve the message-from-adapter-error util

Automatically detect ACL errors
Provide a generic error message as a fallback

ui/app/utils/message-from-adapter-error.js

@@ -1,6 +1,14 @@
+import { ForbiddenError } from '@ember-data/adapter/error';
+
 // Returns a single string based on the response the adapter received
-export default function messageFromAdapterError(error) {
+export default function messageFromAdapterError(error, actionMessage) {
   if (error.errors) {
     return error.errors.mapBy('detail').join('\n\n');
   }
+
+  if (error instanceof ForbiddenError) {
+    return `Your ACL token does not grant permission to ${actionMessage}.`;
+  }
+
+  return 'Unknown Error';
 }